How often should I change the engine oil, and what is the procedure?

Engine oil should be changed after the first five hours of operation and then every 50 hours thereafter. To change the oil, run the engine briefly to warm it, locate the oil drain port on the left side of the engine, attach the oil drain hose to drain into a container of at least 2.5 quart capacity, and refill with new oil per the Engine Operator's Manual specifications. The oil filter, if equipped, should also be replaced at every oil change interval. (Pages 21, 23–24)